A dying operation is now performed on certain synthetic knit yarns while the yarn is wound about a core tube to form a spool of yarn; the core tube being employed to afford means for handling, manipulating or storing the yarn without physical contact therewith. Physical or machine contact with this type of yarn is intentionally avoided in order to prevent it from being "snagged" or "smeared" with dirt or other foreign matter, which might interfere with proper dying thereof.
In that the density/weight of yarn tends to vary from spool to spool and in that the dying time required to achieve any given yarn coloration varies with the density/weight of yarn on each spool, it is necessary to predetermine the precise weight of each spool, if the yarn on all spools being treated is to acquire the same color. Heretofore, it has been the practice to weigh spools one at a time and by hand, due to the difficulty presented by the requirement that machine contact with the yarn be avoided.